JPH058787A - Bicycle crank mechanism having doubled length of crank - Google Patents

Abstract

PURPOSE:To produce rotational torque increased about two times so as to increase velocity about two times and save force about one-half by connecting a crank lever which is extended two times in length relative to the conventional one to the ends of a hanger shaft through a following section, medium section and prime section. CONSTITUTION:One end of a fulcrum shaft support arm 1 and a following section 2 are connected to the ends of a hanger shaft respectively. A crank lever 4 secured to a pedal shaft B at the one end thereof is secured to a prime section 5, and is coupled to the other end of the fulcrum shaft support arm 1 through a fulcrum shaft 3. After adjustment is carried out in such a manner that the fulcrum shaft 3, hanger shaft A and pedal shaft B are placed in an identical plane face and the hanger shaft A is positioned between the fulcrum shaft 3 and the pedal shaft b, a medium section 6 is disposed between the prime section 5 and the following section 2. If the crank mechanism constructed as the above is mounted at the left side of a bicycle, a chain ring 7 is secured to the hanger shaft A at the right side of the bicycle additionally to the above construction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a crank lever having a doubled crank length, which doubles the rotational torque amplified by a crank lever to a hanger shaft.
It relates to the crank mechanism of a bicycle, which is transmitted to the chain ring.

[0002]

2. Description of the Related Art Generally, as a prior art, in a bicycle driving force generator, an input from a petal by human power is transmitted to a crank, and is transmitted as a rotational torque to a hanger shaft fixed to the other end of the crank. It is transmitted from the chain ring that is firmly connected to the rear gear through the chain, and gives the rear wheel a driving force. The magnitude of the rotational torque is determined in proportion to the magnitude of the input by human power and the crank length. Therefore, the longer the crank length, the greater the rotational torque obtained,
Since the width of rotation of the foot of the human body and the height of the hanger above the ground from the center axis of the hanger shaft to the ground are naturally limited, the conventional method of fixing one end of the crank directly to the hanger shaft dramatically increases the crank length. It was not possible to increase the length of the crank, and the usual crank length was around 16 cm. Therefore, the conventional technology has not been able to achieve a dramatic speedup or labor saving.

[0003]

SUMMARY OF THE INVENTION In the prior art,
The crank length cannot be dramatically increased from the current state. Therefore, it is difficult for the conventional bicycle having a crank mechanism to achieve a drastic speedup and labor saving over the current state. The present invention aims to eliminate the above-mentioned drawbacks. That is, while keeping the turning radius of the crank the same as that of the conventional one, by increasing the length of the crank, which is a factor of the generation of the turning torque, by 2 times, the magnitude of the turning torque is increased by 2 times.
This is to double the speed, speed up nearly twice that of conventional bicycles, and reduce labor by almost half.

[0004]

The structure of the present invention will be described. [A] One end of the fulcrum shaft holding arm (1) and a follower (2) are connected to the end of the hanger shaft (A). Stick to it. [B] The fulcrum shaft (3) fixed to the other end of the fulcrum shaft holding arm (1) by fixing the original node (5) to the other end of the crank lever (4) fixed to the petal shaft (B) at one end It is attached as a pivotable pin joint. [C] The fulcrum shaft (3) and the central axis of each of the hanger shaft (A) and the petal shaft (B) are on the same plane or close to the same plane, and the fulcrum shaft (3) and the petal shaft (B) Adjust the condition so that the hanger shaft (A) comes between the two), and the intermediate node (6) to the original node (5) and the follower node (2).
Through. [D] If the above is the left crank mechanism of the bicycle of the present invention, the right crank mechanism of the bicycle has the above [A] to [C].
In addition, the chain ring (7) is fixedly connected to the hanger shaft (A). A bicycle crank mechanism configured as described above.
To add a little explanation about the concept of the element, when the fulcrum shaft holding arm, the fulcrum shaft and the follower, and the crank lever and the master are integrally formed by casting or welding, etc. However, only in this case, due to the differentiation of the functions, they are treated as an original set of separate elements.

[0005]

The operation will be described based on the configuration of the present invention. The force input from the petal shaft (B) by human power is due to the crank lever (4) having a length that is twice as long as the conventional crank length. Produces rotating torque. The torque is once converted into a linear force via the intermediate node (6) and is transmitted to the follower node (2). The linear force is converted into a rotating torque again by the follower and acts on the hanger shaft (A) fixedly connected. Since the fulcrum shaft (3) and the crank lever (4) are pin-joined, only the moment of the crank lever generated around the fulcrum shaft is a moment, and no linear force in the tangential direction on the rotation circumference is generated. .
Therefore, during this period, there is no principle where the force is attenuated, and accordingly, the rotating torque twice as large as the conventional torque is transmitted to the hanger shaft (A). {However, when the intermediate node is a gear as in "Fig. 9", the force is transmitted as it is as a rotational force without changing to a linear force. } The crank lever (4) and the fulcrum shaft holding arm (1) are
Since the fulcrum shaft (3) is pin-joined via the rotatable shaft attachment, the moment of force is not transmitted, and therefore the rotational torque is not reduced in principle here either. Since the hanger shaft (A) is fixed to the fulcrum shaft holding arm (1) and the follower (2), they make the same periodic motion. Further, since the crank lever (4) and the knuckle (5) are fixed, they make the same periodic motion. Then, the medial node (6) for immediately transmitting the motion is applied to the original node (5) and the follower node (2). Therefore, the movement of the crank lever (4) immediately causes the other required elements of the mechanism to undergo a simultaneous and irreversible chasing movement.
In addition, the same periodic motion in the above means a rotary motion having the same rotational angular velocity with the axis of the hanger shaft (A) as the center of rotation. The fulcrum shaft (3) secures one end of the crank lever (4) by the fulcrum shaft holding arm (1) in a positional relationship in which the fulcrum shaft holding arm (1) is always kept at a constant distance from the axis of the hanger shaft (A). . On the other hand, the center point of the rotational movement of the crank lever (4) coincides with the axial center position of the hanger shaft (A) in cooperation with the intermediate joint (6) interposed by the required adjustment. And, it is the fulcrum shaft (3) that directly induces the rotational movement, but the change of the position is caused by the crank lever (4). Here, the main body of the rotational movement and the object are simultaneously generated, and are irreversibly separated. Therefore, the pin joint of the fulcrum shaft (3) does not cause adhesion due to the strain due to the displacement of the movement, but in principle it functions as the original pin contact and transmits the moment of force. Not at all. Also, the rotation stroke of the crank lever (4) is the same as the rotation stroke of the crank of the prior art, regardless of the amplification of the length of the crank lever. That is, the radius of rotation is the distance from the petal shaft to the hanger shaft. Depending on the above,
The crank mechanism of the present invention has the same rotary stroke as the crank of the prior art, but can double the rotary torque. That is, assuming that the conventional crank length is L, the length of the crank lever is twice that of 2L, and the input from the betatal shaft is R, the torque generated on the hanger shaft is LR in the prior art, In the crank mechanism of the present invention, a torque of 2LR is generated in the original node at the position of the fulcrum shaft, and transmitted through the intermediate node and the slave node,
As it is, it will generate 2LR torque on the hanger shaft. Next, the operation of the fulcrum shaft provided with the vertically oriented weight will be described. When both joints of the fulcrum shaft (3) provided with the vertical orientation weight (8), that is, the joints of the fulcrum shaft holding arm (1) and the crank lever (4) are pivotally attached together, Since the center of gravity of the fulcrum shaft is deviated due to the action of the weight, the fulcrum shaft is always in the vertical direction regardless of the position of the rotation stroke of the crank lever (4) and the fulcrum shaft holding arm (1). Will maintain a certain posture. That is, even if the bearing rotates, the shaft does not rotate, so that a perfect pin contact occurs between the shaft and the bearing. Therefore, it is impossible that the torque generated by the crank lever (4) is directly transmitted to the fulcrum shaft holding arm (1) through the fulcrum shaft and the meaning of the mechanism is lost. It should be noted that the method of joining the fulcrum shaft (3) and the required element is a method in which one-side fixing and the other-side element attachment are appropriate, but the point is that it is sufficient if torque bending stress is not transmitted between the required elements. Therefore, it is not always necessary to use a rotatable pivotal attachment, and it is sufficient to use a pin joint having play that does not transmit the bending stress. Now, the length of the crank lever is set according to the following relational expression. 2 x crank length of prior art ≥ length of the crank lever> crank length of prior art + α α is a dead space such as a medial node. {However, in the case of application to a human-powered airplane, it is not necessary to consider the ground height of the crank, so the length of the crank rehaggy can be doubled or more. } The rotation stroke is the same as that of the prior art crank, regardless of the length of the crank lever. Therefore, the most efficient length of the crank lever is to double the crank length of the prior art. Next, the number of teeth of the gear of the chain ring (7) will be described. Generally, in the prior art, the number of teeth of the front outer gear is 50th and the number of top gears of the rear freewheel is 14th. The front to rear gear ratio should be 6 or less.
Therefore, it is appropriate that the number of teeth of the chain ring (7) is 70 to 80. Further, as a matter of course, since the crank lever can be rotated in the reverse direction so as to idle, just like the conventional bicycle, the driving method is the same as that of the conventional bicycle, and there is no inconvenience.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. [A] A petal shaft (B) is fixedly screwed to one end of the crank lever (4), and a bearing hole (9) is provided at the other end in parallel with the petal shaft (B). An arm serving as a boss (5) is projectingly fixed to the outer peripheral portion of the bearing hole so as to form a right angle with the longitudinal direction of the crank lever and the axial direction of the bearing hole. [B] The fulcrum shaft (3) is attached to one end of the fulcrum shaft holding arm (1).
Is fixedly screwed in parallel with the hanger shaft, and a mounting hole (10) for the hanger shaft (A) is provided at the other end.
An arm as a follower (2) is protrudingly fixed to the outer peripheral portion of the mounting hole so as to form a right angle with the longitudinal direction of the fulcrum shaft holding arm and the axial direction of the mounting hole. The mounting hole is inserted into the tip of the hanger shaft and fixed with a fixing bolt (11). {The tip of the hanger shaft (A), which is the joint of the mounting hole (10), is about 1.5 times longer than the conventional one. } [C] Insert the bearing hole (9) of the crank lever (4) into the fulcrum shaft (3) and attach the shaft. Adjust the fulcrum shaft (3) so that the fulcrum shaft holding arm (1) and the crank lever (4) overlap when viewed from the side,
A rigid bar serving as a medial joint (6) is provided at the ends of the arms of the original joint (5) and the follower (2). [D] When the bar is joined to the master and the follower via pins, if both the master and the follower are pin-joined, the bar becomes an intermediate node as shown in FIG. The crank mechanism is in the category of "2." When the bar is formed into a pin joint with proper play on either the original side or the follower side, and the other is fixed to form a rigid joint, the bar is included in the element of the rigid joint. The intermediary node disappears and becomes the crank mechanism within the scope of claim 1. {It is possible when the crank lever is relatively short and the master and follower are close to each other. } [E] When the above bar is transmitted to the original side and the follower side due to the abutting which is improperly and improperly contacted so that only the pushing force is transmitted as a linear force, a link as shown in Fig. 7 is created. The device serves as an intermediary node of the device, and the crank mechanism falls within the scope of claim 2.
{The intermediate node of the link device is formed by pin-joining the connecting rod (12) engaged with the bar by pin-joining to the side surface of the fulcrum shaft holding arm (1). } Next, when the bar is abutted on either the original side or the follower side and the other is fixed and rigidly joined, the bar is included in the element of the rigidly joined side and the intermediate node Disappears, and the crank mechanism falls within the scope of claim 1. [F] As another embodiment, the crank mechanism as shown in FIG. 8 in which sprocket is used for the master and follower and a chain is used as the intermediary. Also, a fulcrum shaft holding arm (1) is used as the intermediate node by using gears for the original node and the follower node.
The crank mechanism as shown in FIG. 9 in which an odd number of gears are axially mounted on the side surface of the crank mechanism. Also, a wire rope can be used as an intermediary node as shown in FIG. "FIG. 11" has the same meaning as "FIG. 1". [G] As shown in FIG. 6, the fulcrum shaft holding arm (1) and the portion of the crank lever (4) that receives the fulcrum shaft are both rolling bearings (13), and are used for vertical orientation in which the center of gravity is deviated. The crank mechanism of "a" to "f", which is formed by pivotally mounting a fulcrum shaft (3a) provided with a weight (8). The scope of "claim 3" is included in this.

[0007]

As described above, the crank mechanism of the present invention can generate twice the rotational torque with the same rotational stroke as the conventional bicycle. Therefore, it can be said that the speed can be doubled and the labor can be reduced to half. In addition, the principle of the crank mechanism of the present invention is widely applied as a crank of an internal combustion engine or a turbine engine, and also as an output amplifier, and can be used in various fields of energy use. Technology.

[Brief description of drawings]

FIG. 1 is a perspective view of the present invention.

FIG. 2 is a plan view of the present invention.

FIG. 3 is a front view of the right crank mechanism / chaining chain of the present invention.

FIG. 4 is a sectional view taken along line I-I ′.

FIG. 5 is a sectional view taken along line II-II ′.

FIG. 6 is a cross-sectional view around a fulcrum shaft provided with a vertically oriented weight as a rolling bearing.

FIG. 7 is a perspective view of the present invention.

FIG. 8 is a perspective view of the present invention.

FIG. 9 is a perspective view of the present invention.

FIG. 10 is a perspective view of the present invention.

FIG. 11 is a perspective view of the present invention.

[Explanation of symbols]

A ・ Hanger shaft B ・ Petal shaft C ・ Chain 1 ・ Fulcrum shaft holding arm 2 ・ Follower 2a ・ Blade bolts for edge 3 ・ Fulcrum shaft 3a ・ Fulcrum shaft 3b with vertical weights ・ Fulcrum shaft Crab hole bolt 3c that forms the edge of the end portion ・ Clic hole bolt that forms the edge of the fulcrum shaft end 3d ・ Tightening nut 4 for screwing and fixing the fulcrum shaft ・ Crank lever 5 ・ Master node 5a ・ Blade bolt for edge 6 ・ Intermediate joint 7 ・ Chain ring 8 ・ Vertical weight 9 ・ Bearing hole 10 ・ Hanger shaft mounting hole 11 on fulcrum shaft holding arm ・ Fixing bolt 12 ・ Link device intermediary Connecting rods at nodes 13 ・ Rolling bearings

Claims (3)

[Claims] (A) One end of a fulcrum shaft holding arm (1) and a follower (2) are fixed to the end of a hanger shaft (A) either directly or in a connecting manner. [B] The original node (5) is fixed to the other end of the crank lever (4) having the petal shaft (B) fixed to one end, and the other end of the fulcrum shaft holding arm (1) is connected to the other end via the fulcrum shaft (3). Pin-join. (C) Engage the original section (5) and the follower section (2) The bicycle crank mechanism configured as described above. 2. The bicycle crank mechanism according to claim 1, wherein the intermediate section (6) is interposed between the original section (5) and the follower section (2). 3. A vertically oriented weight (8) for causing a deviation of the center of gravity, which is provided on a part of a fulcrum shaft (3) which is rotatable about both joints. Bicycle crank mechanism.